1. Field of the Invention
This invention relates to centrifugal pumps of the kind that are used for pumping the oxygenated water to circulate in a culture pond and also for blowing out a large quantity of bubbles which are liable to spread over said centrifugal pumps.
2. Description of the Prior Art
Pumps of this kind have heretofore been constructed with additional floaters and suction pipes extending from the bottom of the pump for absorbing water near the bottom of the pond, resulting in unsteady operation and insufficient improvement of water quality. The centrifugal pump makes a big noise since oxygenation is usually carried out above the water. Another shortcoming of conventional centrifugal pumps is that a large quantity of bubbles are produced through oxygenation to spread over an electric drive motor entirely and also to cause a possible current leakage.